Surgical Treatment of Childhood Pulmonary Hydatidosis: An Analysis of 25 Cases.

Background
Hydatid cyst disease is caused by the parasite Echinococcus granulosus and it is an important health problem in the childhood period. In the present study, we aimed to report our experience in 25 surgically managed pediatric hydatid cyst cases under the light of the relevant literature.


Materials and Methods
We retrospectively analyzed 25 patients below 15 years of age who were treated for pulmonary hydatid cyst at our clinic between 2005 and 2016. The patients were analyzed for age, sex, signs and symptoms, diagnostic methods, cyst localization, diameter, number, treatment modalities, mortality, morbidity, and recurrences.


Results
Of the 25 patients included in this clinical study, 16 were male and their mean age was 10.5 (range 5-15) years. The most common presenting symptom was paroxysmal cough which affected 18 patients. The cysts were located in lungs in 23 patients and lungs and liver in 2 patients. Nineteen pulmonary cysts were solitary, and 21 (66%) were in the lower lobe. Thirteen (52%) patients had perforated cysts. Fourteen (56%) patients were operated with cystotomy and capitonnage, 9 (36%) with cystotomy, and 2 (8%) with enucleation. No case of recurrence was observed during an average 12 (range 8-18) months of follow-up.


Conclusion
Surgery is the primary treatment of pediatric pulmonary hydatid cyst disease. Cystotomy and capitonnage is the most commonly used parenchyma sparing technique.


INTRODUCTION
Hydatid Cyst (HC) disease is caused by the parasite Echinococcus granulosus. It is particularly common in societies engaged in agriculture and livestock breeding, and is endemic to many regions around the world. The disease is transmitted via fecal-oral route, with humans being an intermediary host in the disease's cycle.
Whereas the cysts most commonly reside in the liver, pulmonary involvement is more common in children (1,2). Pulmonary cysts are more commonly located in the lower lobe of the right lung (1). As the disease's clinical signs and symptoms depend on a cyst's size, they may remain subtle for prolonged periods. The primary symptoms of pulmonary involvement are chest pain, cough, and hemoptysis (1,2).
In the present study, we aimed to report our experience in 25 surgically managed pediatric HC cases under the light of the relevant literature.

MATERIALS AND METHODS
We retrospectively analyzed 25 patients below 15 years of age who were treated for pulmonary HC at our

Statistical analysis;
The study data were analyzed using SPSS for Windows

RESULTS
Sixteen patients were male and 9 were female. The mean age was 10.5 (range 5-15) years. The most common symptom in patients with pulmonary HC was paroxysmal cough ( Table 1)     and its prevalence is about 50 per 100,000 (3,4).
Whereas hydatidosis is more common among women than men in adults, male children are more commonly are reportedly affected more commonly than their female counterparts (5). Most of our patients were male, with a male/female ratio of 1.8.
Although HC most commonly involves liver, pulmonary involvement is more common in children (1,2,6). The majority of cysts are asymptomatic.
Symptoms emerge depending on cyst enlargement and involved organ (7). Due to the delay in the diagnosis, the cysts were detected as larger sized cysts (8). Five of our 12 patients had a cyst size equal to or greater than 5 cm. Pulmonary involvement of HC most commonly causes chest pain, cough, and hemoptysis (4,9). Our patients' symptoms were consistent with previous reports.
Conventional chest radiograms are the most valuable diagnostic modality for diagnosing pulmonary HC.
Serological tests combined with chest radiogram aid clinicians for reaching a definitive diagnosis. However, radiological imaging tests are more reliable than serological tests (9). Thoracic CT is valuable for detecting cysts that are invisible in PA chest radiograms or determining the density of intact cysts (9). We also managed to diagnose the condition with the help of these two modalities.
In chest radiogram, ovoid or spherical opacities are diagnostic of non-complicated pulmonary cysts while airfluid level or more specific signs such as lotus or meniscus sign are diagnostic for complicated cysts (1). In a 196-case series were diagnosed the disease with chest radiograms in 132 cases, tomographic examinations in 40 cases, and ultrasonography in 24 cases (6).
It was reported that lung involvement is usually solitary but may be multiple in 14-30% of cases, with the disease favoring the lower lobes (10,11). In a series comprising 1055 cases it was reported that 60% of cases were right-sided, 38% were left-sided, 2% were bilateral, and 75 patients had multiple pulmonary cysts (1). In another study it was reported that cysts were left-sided in 48.9% of cases, right-sided in 40.3%, and bilateral in 10.8% (6). Our cases were solitary in 21 patients, bilateral in 2 patients, and hepatic and pulmonary combined in 2 patients.
The main treatment for lung cyst is surgery (12). The surgeon's goal is to remove the cyst with the membrane, to eradicate the parasite without forming a contaminant, and to close the remaining cavity (12). The choice of surgical technique depends on the condition of the tissue surrounding the cyst during surgery. Commonly accepted procedures in surgery are parenchymal protective procedures (13). While all a l i v e parasitic material is removed, especially in children, the intact lung tissue should be preserved to a maximum extent. The most common surgical method is cystotomy and capitonnage (13). We also used it for 14 of our patients.
In bilateral HC, one or two stage surgical approach should be considered. Primarily, the surgery should be performed on the area with the larger cyst or containing a larger number of cysts in the cases of the uncomplicated cysts for which two stage approaches is preferred (14).
The cysts were bilateral in two of our cases. There were cysts in the both areas of a case, whereas there was one cyst on the left; two cysts on the right in the other case.
Thus, we planned our priority according to the area with larger cyst and containing a larger number of cysts as indicated in the literature.
The most common early complications of isolated HC disease are atelectasis, prolonged air leak, pneumonia, and empyema, and the late complication is recurrent HC disease (11,13). Two of our patients developed prolonged air leak, one developed atelectasis, and another one developed wound infection.
As an alternative to surgical treatment, benzimidazole derivatives, which is used for the medical therapy of HC disease, are recommended for four days before and 1-3 months after surgery to minimize the spread of cyst content in an attempt to prevent anaphylactic reactions and secondary recurrences (15). We used albendazole at a dose of 10 mg/kg in 20 cases for 4-8 weeks postoperatively in an attempt to prevent disease recurrence and spread.
HC disease usually portends a favorable prognosis.
Depending on a cyst's localization and surgeon's experience, the recurrence rates vary between 2 and 25%.
Depending on the same factors, operative mortality ranges between 0.5 and 4% (13). No case of recurrence or death occurred in our study population.
Limitations of our study include retrospective evaluation of events and failure to reach all data related to events.

CONCLUSION
HC is common in our country, and pulmonary involvement is more prevalent among children.
Pulmonary HC disease should be frequently considered in the differential diagnosis of patients with nonspecific symptoms such as chest pain, hemoptysis, and fever, and radiological signs of the disease. The disease is surgically treated, with parenchyma sparing techniques being preferred in the pediatric age group.

Scientific Responsibility Statement
The authors declare that they are responsible for the article's scientific content including study design, data collection, analysis and interpretation, writing, some of the main line, or all of the preparation and scientific review of the contents and approval of the final version of the article.

Animal and human rights statement
All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee and with the Helsinki declaration and its later amendments or comparable ethical standards.

Conflict of interest
None of the authors received any type of financial support that could be considered potential conflict of interest regarding the manuscript or its submission.